Sex-linked inheritance in Drosophila

T.H. Morgan (1910) for the first time discovered sex-linkage in Drosophila melanogaster. Morgan when experimenting noted the sudden appearance of one white-eyed male (mutant form) in the culture of normal red-eyed Drosophila. This white-eyed male was crossed with red eyed female. The F1 flies (both male and female) were all red-eyed indicating that white eye colour is recessive to the normal red eye colour.